Device for controlling the swing of trailer vehicles



w. T. HANNA 2,461,212

DEVICE FOR CONTROLLING THE SWING OF TRAILER VEHICLES Feb. 8, 1949.

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DEVICE FOR GONTROLLVING THE SWING OF TRAILER VHICLES Feb. 8, 1949.

2 Sheets-Sheet 2- Filed NOV. 17, 1947 IJs/VEA/TR.v WML/AM 7.' #ANNA BYmw HIS ATTRNEYS' Patented Feb. 8, 1949 UNITED STATES ATENT OFFICE DEVICEFOR CONTROLLING THE SWING 0F TRAILER VEHICLES William T. Hanna,Cincinnati, Ohio Application November 17, 1947, Serial No. 786,469

(Cl. 28m-33.05)

17 Claims. 1

This invention relates to a device for Vcontrolling the swing of atrailer vehicle, and more particularly pertains to such a device,operated under combined control of the tractor vehicle steeringapparatus and the swing of the trailer vehicle with respect to thetractor vehicle, for forcing the trailer vehi-cle, drawn by the tractorvehicle, to track therewith.

The novel device, in use, rigidly holds the trailer vehicle in adjustedlongitudinal alignment with the tractor vehicle under conditions ofrectilinear` movement or constant curvilinear movement, but permits thetrailer vehicle to deviate from such longitudinal alignment, when thetractor vehicle is turned, by the steering apparatus, one way oranother, s-o as to permit it to come to a proper track with the tractorvehicle. Upon the operation of the steering mechanism oi the tractorvehicle, from straight ahead position, a corresponding deviation of thetrailer vehicle, from its then straight longitudinal alignment with thetractor vehicle, is permitted, whereupon the trailer vehicle and tractorVehicle are held in such deviated alignment. On

return of the tractor vehi-cle to straight ahead position by operationof the steering mechanism,

the trailer vehicle is permitted to swing back to its straightlongitudinal alignment with the tractor vehicle, whereupon it becomesheld secured insuch alignment.

This device is for use with two-wheeled trailer vehicles, the wheels ofwhich are located under the rear portion of the trailer bed, and whichvehicles are primarily drawn by means of pins, projecting downwardlyfrom the front end of the trailer vehicle bed, on its longitudinalcenter line. Such are ordinarily held in the center of a, .so-calledfth-wheel, -which comprises a plate with a V-shaped slot therein,mounted on the rear end of the tractor vehicle, said slot ending in acentral aperture located on the longitudinal center line of the tractorvehicle, vUnder ordinary circumstances, therefore, a trailer vehicledrawn by such a pin follows, 0r tracks, the tractor vehicle byentrainment therewith. With a heavily loaded trailer vehicle, especiallywhen such Vehicle is loaded so as not to be evenly balanced, there is atendency for such vehicle to set -up adynamic response to vibrationscaused by travel over rough roads, which commonly ends in a dangerousswinging or sh-tailing of the trailer vehicle. Another dangeroussituation arises by reason of the tendency of a heavily loaded trailerto skid to'a jackknifed position with reference to the tractor vehiclewhen the tractor vehicle suddenly stops. This phenomena occursfrequently when roadways are slippery and especially when a tractor'vehicle and its trailer vehicle are rounding a curve.Y

It is an object of this invention to couple a tractor vehicle to itstrailer vehicle, by a means additional to the primary coupling,selectively controlled by the movement of the steering mechanism, sothat the trailer vehicle will always come to and 'be heldin propertracking alignment with the tractor vehicle whether on straight-awaytravel or on rounding curves.

Another object of the invention is to provide such a device whichcontrols the tracking of a trailer vehicle with its tractor vehicleaccording to the degree of deviation from a set position that thesteering wheels are turned.

Another object of the invention is to provide a fluid-type of torquecoupling foruse between a trailer vehicle and its tractorvehicle, inwhich the movement of the uid is controlled by a valve actuated to openposition Vfrom a normal closed position by movement of the steeringmechanism from set position and which valve is returned to normal closedposition upon the trailer assuming a deviation from previous alignmentwith the tractor vehicle according to the amount of turn given thesteering wheels.

YAnother object of the invention is to .provide controlled means formechanically holding a trailer vehicle in an adjusted alignmentwith itstractor vehicle. Y

Another object of the invention is to provide mechanism which permitstracking of a trailer vehicle behind a tractor vehicle without danger ofjackkning. Y

Further objects, and objects relatingto the details and economies ofconstruction willy deflnitely appear from the detailed descriptionitofollow. In one instance, I have accomplished the objects of my inventionby the devices and means as set forth in the following specication. Myinvention is clearly defined and pointed out in the appended claims. A

Structures, constituting the preferred embodiand 29 Vthrough tie rod 25.

ment of my invention., iilustrated in the accompanying drawings, forminga part of this specification, in which:

Fig. 1 is a plan view of the essential running gear of a tractor vehicleand its associated two wheeled trailer vehicle, primarily coupledtogether, by a standard pivot coupling, and additionally coupled by thenovel swing control mechanism.

Fig. 2 is a plan View of the substance of Fig. 1.

Fig. 3 is a longitudinal section through the hydraulic cylinder andvalve portion of the swing control device.

Fig. 4 is a section through the valve, showing the valve plug in full,and showing the crank and noating lever attached thereto.

Fig. 5 is a view of a typical floating lever provided with a pluralityof pivot holes, to enable adjustment of it to different vehicles.

Figs. 6 to 1D, inclusive, show, in sequence certain of the positions ofthe floating lever and valve crank during a left turn and recoverytherefrom.

The same Vreference numerals are used for the same parts throughout theseveral views.

Referring, rst, to Figs. 1 andV 2, I show a tractor vehicle framework 26supported on a forward axle 2i land a rearward axle 22. Front Wheels 23`and 24 are rotatably mounted on axleheld steering knuckles 26 and 21,respectively, on which they are turned by steering arms 28 Thiscomprises what will loe called the steering mechanism, in the disclosureto follow, said mechanism being operable by any means, such as asteering wheel and gearing'ordinarily used in such vehicles. Turning ofthe wheels one way is accompanied by an associated shift of tie rod 25,and, when the wheels are `turned the other way, the tie rod shifts inthe opposite direction. This shift in the rod is used to control thenovel mechanism to he described, although any other shifting or movingpart in the steering mechanism could be used` The rear end of thetractor vehicle is supported. on axle 22 having on either end thereof aset of supporting and driving wheels comprising wheels 35, 3l, 38 and39. The trailer is provided with an axle 3Q secured beneath the bed 34of the trailer, crosswise thereof, near the rear end, and said axle hason either -end thereof supporting wheels comprising wheels 3l, 32, 33and 34.

The front end of the trailer has afdownwardly extending pin 40 (see Fig.l) which'ts into a V-shaped slotl on a fifth wheel 42 pivotallysupported, as at 43, on the rear end of the tractor vehicle, in the wellknown manner. Pin 40 is on the longitudinal center line of the vtrailervehicle and the central portion of the fth wheel 42, into which the pin40 is positioned, is on the center longitudinal line or the tractorvehicle. The pin 4is 'held in the slot 4! by locking devices, whichpermits the tractor Vehicle and the trailer vehicle, .unless otherwiserestrained, to swing with respect to one another around the center ofpin 48,l vThis `is the ordinary mode of Yattaching such a-trailervehicle to such a tractor vehicle, and, in making turns, thelongitudinal alignment of the tractor -vehicle and the vehicle change toaccommodate the system to the curve being rounded.

It is this free pivoting that `the novel device, disclosed herein,controls, permitting such turning on the pivotV only when the steering`mechato the frame of the tractor vehicle.

4 nism is actuated from a steady state of adjustment and then only tothe degree of actuation of the steering mechanism from such state ofsteady adjustment.

Mounted on cross member 43a of the tractor vehicle, on a vertical stud4t secured in said member 43a is a gear 45 having secured thereto, andextending rearwardly therefrom, an arm 4S having extending upwardlytherefrom a stud 41 adapted to slidably engage in a slot 48 cut in thebottom of the bed of the trailer vehicle, the longitudinal axis of theslot being in the longitudinal center line of the trailer vehicle. As analternative, the slot may be in the arm it and the stud attached to thetrailer vehicle. Also attached to the member 4ta is a cover plate 48extending upwardly and over the gear and forming on one side thereof ahousing in which a rack member 5t may slide back and forthlongitudinally of the tractor vehicle, the teeth 5l on said rack mem-oerengaging the gear 45 so that, in the event that the tractor vehicle andtrailer vehicle change in their alignment, around pin 4G, the gear willbe turned and the rack 55 will be shifted one way or another,accordingly.

' Integral with rack 5!! is a piston rod 52, connected to rack' by oisetmember' 53a, said piston rod having on its other end a piston 53 l(Fig.3) reciprocable in a cylinder 54 attached The parts are so arrangedthat, when the tractor vehicle andthe trailer vehicle are in straightalignment, the piston 53 is at or near the middle part of the cylinder,ythat is, at a mid-point between the limits of the full stroke of thepiston in said cylinder. The cylinder is lled with fluid, such ascommonly used in hydraulic devices, the uid iilling` the cylinder exceptfor thatportion which is displaced by the piston, so that said fluid ison both Vvsides of Vsaid piston. VIn the walls of the cylinder there isprovided a port 55 and a port 53, at opposite ends of the cylinder, forpassage of the Ifluid in or out thereof. Port 55 is connected by apassageway 51 to an exit port 58 coupled to a passageway 59 in a valve Sprovided with a rotatable plug 6l, with cross passage- Ways 6l. therein,each, when the valve is turned to openY position for that passageway,leading to passageway $3 which is coupled to passageway 64' which endsat port 55. By turning the valve plug 8l in either direction from normalposition shown herein, in Fig. 3, the port 55 is connected to port 56through one or the other ci said plug passageways E2, permitting thepiston 53 to move one way or another in the cylinder, the fluidtraveling through the valve one Way or another in response to suchmovement. That is, under conditions where the valve 6l connects ports 55and 55, the piston is free to move in the cylinder, which means'that therack 5d (Fig. l) may shift, permitting the trailer to swing one way orthe other. When the valve Sl is closed, as shown in Fig. 3, the piston53 is held stationary and, through piston rod 52, rack 5), gear 45, andmember 46, the trailer is held in whatever aligned positionitl is -thenin, with respect to the tractor vehicle.

Referring to Fig. 4, the valve plug 5l has, secured on the stern 6Eextending from the valve housing 61, a crank 68, pivoted, by pivot stud69 on one end of a iioating lever lil. Y

Referring to Fig. 1, one end of vfloating lever 'Hl is pivoted at 'H toa link '32 pivoted at its other end by pivot 13 to a lever 'I4 mounted'on rod 14a, rotatably mounted at T5 to the tractor vehicle.

The other end of rod 14a has secured thereto a lever 18h pivoted at 'i6to a link ll pivoted at 'I8 to a bracket 18a secured to tie rod 25, sothat, as tie rod shifts, in response to operation of the steeringmechanism, the link l2 will shift forwardly as a right turn is beingmade and shift rearwardly as a left turn is being made. The other end offloating lever 'Ill is pivoted, by pivot 19, to link 8G pivoted at 8| toa clamp 82 secured on piston rod 52.

It will be seen, by reference to Fig. 1, that, if pivot point 'H isstationary and pivot point 19 moves forwardly or backwardly in responseto a shift of the piston, the pivot point 69 connected to the outer endof the valve crank is shifted accordingly. If the pivot point 19 is heldstationary and the link 'l2 is shifted forwardly 01 rearwardly, thepivot (it at the outer end of the valve crank is shifted accordingly.The direction of shift as link l2 moves to the rear, when pivot 'i9 isstationary, is such as to cause the crank 68 to turn counterclockwise,and if link 'l2 shifts forwardly the valve crank will shift clockwise.If piston rod 52 moves to the rear while pivot point 1I is stationary,the valve crank will move counterclockwise and, if piston rod 52 movesforwardly as pivot point 1| is stationary, the Valve crank will moveclockwise.

With the parts arranged as shown, if, for instance, the tractor vehicleis running in a straightforward direction with the trailer vehicle instraight longitudinal alignment therewith, and the driver of the tractorvehicle turns the front wheels to make a left turn, then link 'l2 Vwillmove rearwardly from the position shown in Fig. 6 to the position shownin Fig. 7, opening the valve 6l to permit uid to pass from one side ofthe cylinder tc the other, and, hence, the trailer vehicle is permittedto track with the tractor vehicle, gradually, causing forward movementof the rack 5! and piston rod 52, forcing link 8D 'forwardly as shown inFig. 8. In opening the valve, the valve crank 68 was movedcounterclockwise. As pivot point 'H `is now stationary, it being assumedthat the tractor vehicle wheels have been turned left, the movementforward of link Bll causes clockwise movement of crank 55, which closesvalve E@ preventing the piston rod 52 from moving, thus holding thetrailer vehicle in deviated alignment as the curve is being rounded.Fig. 9 represents the position of the parts as the link 'l2 is beingdrawn forward in response to the turning of the tractor vehicle wheelsto a straight forward position, which, as pivot point l5 is nowstationary, moves crank E3 in a clockwise direction, again opening thevalve, and permitting the trailer vehicle to track with the tractorvehicle until it assumes a position of straight alignment therewith. Asthe link l2 comes to position of straight forward travel as shown inFig. 10, the valve mechanism is brought to closed position at a point`where the trailer vehicle is again in straight longitudinal alignmentwith the tractor vehicle. It should be understood that the successivepositions of the mechanism shown in Figs. 6 to l0 are-taken at variousintermediate and end positions of the parts, and that, in actualmovement cf the parts, there is a gradual succession of intermediatepositions while the parts are being brought to equilibrium position,where the valve is closed, such closure of the valve preventing any moremovement of the rack 5S andihence preventing any more movement, in aswinging action, of the trailer vehicle. The time it takes to open thevalve is, of course, dependent on how fast the steering Wheels areturned.

Fig. 5 shows a floating lever l!) in which holes 83 are provided foradjusting the points at which pivot E9 shall be made, to render themechanism adjustable for use with diiierent vehicles.

The succession of steps of operation of the iioating lever 10, in makinga right turn, is the reverse of the succession of steps of operation inmaking the above described left turn, and the valve plug is providedwith the two passageways t2 so that the valve works in one direction' aswell as the other, with the same response,

It will be understood from the foregoing that, after the steeringmechanism has been brought to rest, the trailer vehicle is permittedsuiiicient swing, throughthe particular dimensions of the elements shownor by adjustment of the floating lever pivot point ld, as shown in Fig.5, so that the trailer vehicle wiil accurately be brought to track withthe tractor vehicle. Therefore, whether in straight ahead rectilinearmovement or in continuous curvilinear movement, the trailer vehicle isalways held in the necessary alignment with the tractor vehicle. It isonly during the actual necessary change in alignment of the vehicles,demanded by the turning of the steering wheels, that the piston ispermitted to move, and, therefore, that is the only time in which thetractor vehicle and the trailer vehicle are permitted to pivot withrespect to one another. f

The consequence of all this is that the rigid coupling of the tractorvehicle and the trailer vehicle, during normal traveling, is maintaineduntil a change of direction is brought about by steering, and, aftersuch change of direction has been accomplished, the rigid coupling againpre- Valls.

I am aware that the structures herein described are susceptible ofconsiderable variation without departing from the spiritof my invention,and, therefore, I claim my invention broadly as indicated by appendedclaims.

Having thus described my invention, what I claim as new and useful anddesire to secure by Y Letters Patent is:

1. In a tractor-trailer vehicularsystem which the tractor Vehicle isequipped with steering mechanism, and wherein the trailer vehicle' is'pivotally connected at its front end to the tractor vehicle at a pointto the rear of steering mechanism thereon, including, in combination,.shiftable means coupled to the trailer vehicle and shifted in adirection and a distance corresponding to the swing of the trailervehicle on its pivot; control means coupled to the shiftable means andnormally holding itfrom shifting but operable to permit such shifting;means actuated by movement of the steering mechanism to operate thecontrol means to permit such shifting of the shiftable means as topermit the trailer vehicle to track with the tractor vehicle; and meanscoupled to the shiftable means and to the control means to return thecontrol means to normal holding condition when the trailer vehicle hascome to tracking alignment. f

2.The combination of claim l in which the trailer vehicle includeswheels under its rear end only. Y

3. The combination of, claim l in which the shiftalole means comprises arack member which is coupled to the trailer vehicle through a gear,pivoted to the tractor vehicle, and an arm secured tothegear at one endand coupled at its other end to the trailer vehicle by a pin and slotcoupling. l

4. `'Ihe combination of claim 1 in which the control means comprises auid-iilled cylinder having a valve-controlled uid passageway joining thecylinder ends, and having a piston which `may be shifted in the cylinderwhen the valve is open, to which piston the shiftable member is coupled,and in which the valve is opened by operation of the steering mechanismand closed by the shifting of the shiitable means.

5. The combination of claim i in which the valve is equipped with aturning crank pivoted to a midpoint of a 'oating lever coupled at oneend Vto the steering mechanism and coupled at its other end to theshiftable means.

6. In a device of the class described, the combination of a tractorvehicle including a frame structure provided wit steering mechanism; atrailer vehicle including a frame structure pivotally connected to theframe structure of said tractor Vehicle; a hydraulic device including arpiston movable in a fluid-filled cylinder, a iluid passagewaycommunicating with each end of said cylinder, and valve means in saidpassageway;

an operative connection between said steering mechanism and said valvefor opening said valve upon actuation of said steering mechanism; an'operative connection between said piston and said trailer vehicle formoving said piston upon displacement of said trailer vehicle angularly,relative to said tractor, around the pivot connection;

. and an operative connection between said piston and said operativeconnection between said steering mechanism and said valve for closingsaid 1 i valve upon completion of said trailer displacement.

T. The combination of claim 6 in which the trailer vehicle has runningWheels only under its rear end and is pivotally coupled at its front endto the tractor vehicle to the rear of the steering mechanism.

8. The combination of claim 6 in which the valve is operable by a crank,in either direction,

Vfrom a normally closed position to an open posif tion, depending on thedirection -of actuation of the steering mechanism.

9. The combination of claim 6 in which the operative connectionbetweenthe piston and the trailer vehicle comprises a shiftable rack ineni vehicle equipped with steering mechanism vto a two-wheeled trailervehicle primarily pivotally coupled to the tractor vehicle, includingincombination, a member coupled to the trailer vehicle and moved adistance proportional to and in Va direction determined by the swingingof the trailer vehicle around its pivot; a member moved by the steeringmechanism proportional to and in a direction determined by movement of`the mechani-sm; and means controlled jointly by the movement of themember attached to the trailer vehicle and by movement of the membermoved by the steering mechanism to hold the trailer vehicle againstswing around its pivot except in an `amount to permit it to track withthe tractor vehicle.

11. The device of claim 10 in which the swing of the trailer iscontrolled through :holding and `8 freeing said member attached to thetrailer vehicle.

12. The device of claim 10 in which the means to control the swing ofthe trailer includes a cylinder, a piston shiftable in the cylinder andhaving a piston rod extending therefrom, a valvecontrolled by-pass ductconnecting the ends of the cylinder, and a iluid llng the cylinder andby-pass duct and in which the valve is controlled jointly by trailerswing and steering mechanism movement.

i3. A device for additionally coupling a tractor vehicle equipped withsteering mechanism to a two-wheeled trailer vehicle primarily coupled tothe tractor vehicle by a pivot pin, including, in combination, afluid-containing cylinder equipped with a piston having a piston rodextending exteriorly thereof and having an external passageway equippedwith a normally closed valve which, when open, permits passage of iuidfrom one side of the piston to the other to permit the piston to move;means coupling the piston rod to the trailer vehicle to one side of thepivot pin to normally hold the tractor vehicle and trailer vehicle inalignment according to the piston position, but so as to permit thetrailer vehicle to pivot one way or another, if the piston is permittedto move, in a direction associated with the direction of piston movementand a distance proportional thereto; and means coupled jointly to thevalve, to the steering mechanism, andV to the piston, to open and closethe valve to permit the piston to move and the trailer to swing in adirection and a distance proportional to the movement of thesteeringmechanism.

14. The device or claim 13 in which the valve is operated by a crank andin which the means coupled to the valve is coupled to the cra-nk andcomprises a cating lever pivoted at one end to the steering mechanism,at the other end to the piston rod, and coupled at a midpoint to thevalve crank.

15. The device of claim 14 wherein the valve lhas a normal closedposition but is turnable by the crank, in either direction, from normal,to an open position, and wherein the ioating lever is coupled pivotallyto the end of the crank. y

16. A device for additionally coupling a tractor vehicle equipped withsteering mechanism and primarily coupled to a two-wheeled trailervehicle by means of a pivot coupling, including, in combination, a gearmounted on the tractor vehicle to the rear of the pivot point and saidgear having integral therewith a rearwardly extending arm pivotallycoupled at its rear end, by a pinv and slot connection, to the trailervehicle; a rack shiftably mounted on the trailer Vehicle and inengagement with the gear, so that the swing of the trailer vehiclerelative to the tractor vehicle causes the rack to shift one way or'theother; a closed fluid-filled cylinder equipped with a piston and havinga piston rod extending exteriorly thereof, said exten-ded portion of thepiston rod being connected to the rack, so that the rack shifts with thepiston, and said cylinder having a fluid port at either end; meansconnecting said ports, externally or the cylinder for fluid transfer,said connecting means including a valve turnable either way from anormal closed position to an open position, and said valve beingequipped with .a crank for turning; a lever pivoted at a midportion tothe crank end, pivoted at one end to a member secured to and moving withthe piston rod, and pivoted at its other end to the steering mechanism`of the tractor vehicle so the lever .is

shifted one way or the other as the steering mechanism is operated oneway or another from a set condition, the parts being so proportioned andadjusted, relatively, that the valve remains open upon operation of thesteering mechanism until the trailer swings to track with the tractorvehicle, whereupon the valve is closed, the described additionalcoupling then holding the trailer and tractor in such tracking positionuntil the next movement of the steering mechanism.

17. In a tractor-trailer vehicular system in which the tractor vehicleis equipped with steering mechanism, and wherein the trailer vehicle ispivotally connected at its front end to the tractor vehicle at a pointto the rear of the steering mechanism thereon, including, incombination, movable means supported upon one of said vehicles,operatively connected to the other of said vehicles and susceptible tomovement in either direction from a substantially midway position to anextent corresponding to the angular dispiacement of one oi' saidvehicles relative to the other when the vehicular system is traveling ona WILLIAM T. HANNA.

No reference cited.

